The nonspecificity of the lead method for the histochemical demonstration of adenosine triphosphatases in human skeletal muscle fibres.

The lead method for the histochemical demonstration of presumptive mitochondrial adenosinetriphosphatase was applied to biopsy and autopsy samples of the human vastus lateralis muscle. The effect of p-chloromercuribenzoate and of Triton X-100 was tested microdensitometrically and the activity of 'mitochondrial' ATPase was compared to the activity of enzymes of the oxidative metabolism succinic dehydrogenase and NAD-tetrazolium reductase. It is concluded that the ATPase activity displayed is not mainly mitochondrial. In autopsy material, it seems to be predominantly myofibrillar.